Corneal dystrophy is an autosomal dominant hereditary disease, which begins with an opacity in the center of cornea and gradually spreads and thus ends up vision loss as a patient gets older. It includes Avellino corneal dystrophy, Granular corneal dystrophy, lattice type I corneal dystrophy, Reis-bucklers corneal dystrophy, etc., and is caused by mutation of a gene coding βIG-H3 protein.
Heterozygous patients suffering from Avellino corneal dystrophy appear to have severe loss of vision as getting older and homozygous patients appear to have complete loss of vision since 6 years old. Avellino corneal dystrophy is a newly named disease in 1988, divided from generally called Granular corneal dystrophy because it was found to have genetic distinction. Also, it has been known to be the most common corneal dystrophy worldwide, 1/340 to 1/1000 of prevalence rate in Korea (the case of heterozygote) based on genetic analysis indicates that it is a common dystrophy (Holland, E. J. et al., Ophthalmology, 99:1564, 1992; Kennedy, S. M. et al., Br. J. Ophthalmol., 80:489, 1996; Dolmetsch, A. M. et al., Can. J. Ophthalmol., 31:29, 1996; Afshari, N. A. et al., Arch. Ophthalmol., 119:16, 2001; Stewart, H. S. Hum. Mutat., 14:126, 1999).
The present inventors have found that if a heterozygous Avellino corneal dystrophy patient has LASIK surgery, about 2 years later, opacity of cornea starts to develop aggressively and eventually results in vision loss (Jun, R M et al., Ophthalmolgy, 111:463, 2004). Previously, eye surgery has been performed with an expectation that LASIK or Excimer Laser surgery would get rid of vision blurriness of a patient suffering from corneal dystrophy. Also, even in Korea, approximately 3 hundred thousand cases of LASIK surgery have been performed, which leads to the assumption that 300 people lost their vision, based on 1/1000 of minimum estimation of heterozygous patients suffering from Avellino corneal dystrophy. Patients who have undergone LASIK surgery are mainly in their 20's and 30's carrying out productive activities; therefore, their vision loss causes serious troubles in both society and economics. In addition, after approval of LASIK surgery since the year 2000 in USA, Avellino corneal dystrophy patients who underwent LASIK surgery have been found to lose eye sight among African American, which infers that plenty of similar cases might be occurring throughout the world.
However, although accurate diagnosis of Avellino corneal dystrophy is required to prevent the progression of Avellino corneal dystrophy by LASIK surgery, the diagnosis of Avellino corneal dystrophy is just conducted by microscopic observation of corneal opacity, and thus often doctors miss latent symptoms of patients to perform LASIK surgery, which results in vision loss. Therefore, rapid and precise diagnosis of corneal dystrophy is desperately in need.
In addition, in conventional diagnosis, the results of diagnosis may vary depending on variables such as the skill of a doctor and the patient's condition. Thus, the development of diagnostic methods having improved reliability and accuracy has been required.